Buckles for safety seat belts



June 30, 1970 J. H. FREl E1' AL BUCKLES FOR SAFETY SEAT BELTS FiledMarch 1. 1968 2 Sheets-Sheet l June 30, 1970 J. H. FREI E1. AL

BUCKLES Foa SAFETY SEAT BELTS 2 Sheets-Sheet 2 Filed March 1. 1968IIIIIII` M Twin-m United States Patent O 3,517,416 BUCKLES FOR SAFETYSEAT BELTS Josef Hermann Frei, Muhlestrasse 22, Rusclllikon,Switzerland, and Gte Eskil Yngve Holmberg, Anderstorp, Sweden Filed Mar.1, 1968, Ser. No. 709,730 Claims priority, application Sweden, June 30,1967, 10,271/67; Dec. 22, 1967, 17,771/67 Int. Cl. A44b 11/06, 11/25U.S. Cl. 24-75 5 Claims ABSTRACT OF THE DISCLOSURE In a buckle forsafety seat belts having two interengageable buckle parts, a latchingbar is shiftable in one buckle part. A leaf spring interposed betweenthe latching bar and a stationary abutment biases the latching bar intolatching position in which the bar prevents the buckle parts from beingdisengaged from one another.

This invention relates to buckles for safety seat belts comprising twointerengageable buckle parts with abutments for mutual interconnectionpreventing a separation of the buckle parts and a bar on one buckle partwhich is arranged as a latching member and is movably guided in opposedgrooves for translatory movement in its transverse direction between alatching position and a release position in order in these positions toprevent or permit shifting of the abutments out of mutualinterconnection, said bar being spring-biased into latching position.

For the simplification of such a buckle in structural respect on onehand by a reduction of the number of constituents of the bucklemechanism, and on the other hand by a simpler design of the individualconstituents, the present invention provides a buckle of this type whichis characterised by the fact that a leaf spring is interposed betweenthe bar and a stationary abutment on said one buckle part forresiliently maintaining the bar in its latching position.

For better elucidation a pair of buckles chosen by way of example willbe described in the following with reference to the accompanyingdrawings in which:

FIG. 1 is a plan view of the buckle in one embodiment thereof and of alocking tongue inserted therein, the cover of the buckle having beenremoved;

FIG. 2 is a longitudinal section of the buckle and the locking tongue inFIG. 1;

FIG. 3 is a fragmentary front view, partly in cross section, of thebuckle shown in FIGS. 1 and 2;

FIG. 4 is a plan View of the buckle in the other embodiment thereof andof a locking tongue inserted therein, parts of the -buckle being brokenaway to give access to the inner constituents of the buckle;

FIG. 5 is a longitudinal section of the buckle and the locking tongueshown in FIG. 4.

The buckle illustrated in FIGS. 1-3 comprises a U- shaped base platehaving a web 11 and upwardly bent edge flanges 12. Bosses 13 areprovided on the web 11 to extend in an upward direction therefrom and toengage in conforming apertures in a locking tongue 14 which is intendedfor coaction with the buckle. For adjustable fastening in the buckle ofa strap of a safety seat belt a knurled clamping roller 15 is mountedwith its end journals 15a in slots 16 in said flanges 12 for movement inits transverse direction towards and away from an abutment edge 17 ofthe web 11 for clamping the strap between said clamping roller and theabutment edge in the desired fastening position. A correspondingfastening device for a strap can be located on the locking tongue, butis not shown in the drawings.

ICC

A latching member for preventing that the locking tongue 14 isdisengaged from the bosses 13 is constituted by a cylindrical bar 18which is guided with its end journals 19 in the slots 16 for shiftingmovement in its transverse direction to a position, the latchingposition, which is shown in FIGS. l and 2 and in which the bar 18 islocated above the bosses 13 thereby preventing that the locking tongue14 is raised out of engagement with the bosses, and another position,the release position, in which the bar 18 is shifted sufficiently far tothe right as viewed in FIGS. l and 2 to permit the locking tongue to bemoved out of engagement with the bosses 13 thus being released from thebuckle. The shifting of the bar 18 to release position can be performedonly against the action of a spring 20 which resiliently biases the barto latching position, and said spring is a substantially W-shaped leafspring which at its middle portion bears against a stationary abutmentformed by a pin 21 arranged on the web 11, while the two median legs ofthe spring straddle said abutment pin. The outer spring legs are slitlongitudinally to form two tongues 22 and 23 one of which is wider andbears with its rounded end against the bar 18 which has a reduceddiameter in the region where the leaf spring bears against it, while theother tongue is narrower, closer to the web and adapted to have itsrounded end bearing against the locking tongue inserted in the buckle tomaintain the locking tongue engaged with the bosses 13 so as not torattle in the buckle. For the same purpose there is arranged in acentral annular groove in the bar 18 an O-ring 24 of rubber which bearsagainst the upper side of the locking tongue inserted in the buckle andurges the locking tongue into engagement with the web 11.

Manipulation of the bar 18 for releasing the locking tongue from thebuckle is performed by means of a cover of U-shaped cross section, whichis passed onto the base plate 10 with the limbs 26 of the cover situatedon the outer sides of the flanges 12 of the base plate, the end journals19 of the bar 18 and the end journals 15a of the clamping roller 15projecting from the flanges 12 on the outer sides thereof to be receivedeach in a groove 27 in each limb of the cover 25, whereby the cover isretained in position on the base plate 10, in which it completely coversthe buckle mechanism mounted on said base plate, and is shiftable in adirection plane parallel with the base plate. A ridge 28 on the web ofthe cover 25 is adapted, when the cover is shifted to the right asviewed in FIGS. 1 and 2, to carry the bar 18 along so that the latter isshifted against the spring force exerted by the leaf spring 20 from itsillustrated latching position into release position. When the bar 18 isin its latching position the cover is engaged with the end edges of theflanges 12, as shown in FIG. 2, while the ridge 28 engages the bar 18 sothat the cover is kept xed and does not rattle on the bucklesimultaneously as it determines the latching position of the bar 18.

For release of the locking tongue 14 from the buckle the cover 25 isthus shifted to the right as viewed in FIGS. 1 and 2, that is rearwardlyfrom the locking tongue, the bar 18 being carried along into releaseposition. The locking tongue, however, can be inserted in the bucklewithout requiring manipulation of the cover inasmuch as the bar 18 isurged from latching position into release position by the front edge ofthe locking tongue, the bar moving away from the ridge 28 on the cover25 and then snapping back into latching position under the action of thespring 20 after the locking tongue has engaged the bosses 13.

The buckle shown in FIGS. 4 and 5 comprises a U- shaped base plate 10with a web 11 and upwardly bent edge flanges 12. A slot 13 is providedin the 'web 11 and a locking tongue 14 is adapted to engage said slot bymeans of an angularly bent end portion 14'. For adjustable fastening inthe buckle of a strap of a safety seat belt a knurled clamping rollerhaving finger grip means 15a is mounted in slots 16 in the flanges 12for movement towards and away from a bar 17 which is arranged as astationary abutment and which extends between the flanges 12 parallelwith the web 11 to permit clamping the strap in the desired fasteningposition between the clamping roller and the bar 17. Correspondingfastening means for a strap may be provided on the locking tongue butare not shown in the drawings.

Also in this case a cylindrical bar 18 constitutes a latching member forpreventing the locking tongue 14 from being disengaged with the slot 13,and is guided by end journals 19 in slots 36 in the flanges 12 fortransverse shifting movement. In the embodiment illustrated the slots 36are straight and oblique to the web 11 so as to extend from the web in adirection from the left to the right as viewed in FIG. 5. The bar 18 isshiftable between a position, the latching position, which is shown inFIGS. 4 and 5 and in which the bar 18 is in bearing engagement with theupper side of the locking tongue 14, preventing the locking tongue frombeing raised out of engagement with the slot 13, and another position,the release position, in which the bar 18 is shifted sufliciently far tothe right, as viewed in FIGS. 4 and 5, to lie at such a height above theweb 11 that the locking tongue can be disengaged from the slot 13 andthus be released from the buckle. Shifting of the bar 18 to releaseposition, however, can be performed only against the action of a spring20 `which resiliently biases the bar to latching position and which likein the earlier embodiment is a substantially W-shaped leaf springbearing at its middle portion against a stationary abutment formed by apin 21 on the web 11, while the two median legs of the spring straddlethis abutment pin. The outer spring legs bear with their rounded endsagainst the bar 18; these ends are of a slightly smaller width than theremaining leaf spring in order that the locking tongue 14 inserted inthe buckle may go free of them, as Iwill appear from FIG. 5.

Manipulation of the bar 18 for release of the locking tongue from thebuckle is brought about by means of a flap 37 which is in the form of atwo-armed lever and `which is mounted with a pair of mutually spacedlugs 38 on a shaft 39 disposed between and non-rotatably secured in theflanges 12. The flap 37 is biased by a coil spring 4t) -wrapped aroundthe shaft to be normally kept in the position illustrated in which theflap bears against the bar 17, extending over the Iweb 11 between theflanges 12 to cover the space between said flanges and the buckle partslocated therein. The two lugs 38 lie close to the inner sides of theflanges 12 and form spacing elements between the flanges and shoulders18 between the journals 19 and the remaining bar 18 in that the lugs 38partly overlap said shoulders as will appear from FIG. 5. In this lway,the bar 18 is kept in position between the flanges, which isadvantageous in that the bar 18 is easily mounted. It is inserted in theslots 36 before the ilap 37 is mounted, and is then fixed in its correctaxial position between the flanges by pivoting the flap 37 to the shaft39 which is inserted in the flanges. Upon pivotment of the flap 37counterclockwise as viewed in FIG. 5, an edge 41 of the flap 37 isadapted to carry along the bar 18 against the action of the spring 40 sothat the bar is shifted against the force exerted by the leaf spring 20from the latching position illustrated to release position.

The locking tongue 14 can be inserted in the buckle without it beingnecessary to manipulate the flap 37 inasmuch as the bar 18 is therebyurged by the angularly bent edge 14' of the locking tongue from latchingposition to release position independently of the flap 37 and then snapsback to latching position under the action of the spring 20 after thelocking tongue has engaged the slot 13.

-A possible modification of the embodiment of the 4 buckle illustratedin FIGS. 4 and 5 implies providing a curving slot 36 whose center ofcurvature is substantially located on the axis of the shaft 39. However,the arrangement illustrated in which straight slots 36 are provided issimpler from the point of manufacture and does not suffer from anyfunctional drawbacks.

What we claim and desire to secure by Letters Patent is:

1. A buckle for safety seat belts comprising two inter.- engageablebuckle parts, one of said buckle parts having a base plate and angularlybent flanges thereon forming slots, abutment means on each of saidbuckle parts, said abutment means being interconnectible to preventseparation of the buckle parts, a cylindrical bar on said one 'bucklepart, said bar forming ends received by said slots and projectingoutwardly from the flanges through the slots, and being guided in theslots for translatory movement in its transverse direction between alatching position and a release position in order in these positions toprevent and permit, respectively, movement of said abutment means frommutual interconnection, a stationary abutment on said one buckle part,between said bar and said stationary abutment a leaf spring having itsends engaging said bar on one side thereof and between its ends bearingagainst said stationary abutment yieldingly biasing the bar into saidlatching position, operating means for said bar on said one buckle partincluding a cover, an abutment surface formed by said cover to engagesaid bar on the opposite side thereof allowing said bar to betransversely moved against said spring bias relatively to said abutmentsurface out of engagement therewith, and legs on said cover embracingsaid flanges and forming in the sides facing the flanges groovesslidably receiving said projecting ends of the bar to movably guide thecover on said flanges.

2. A buckle as claimed in claim 1, further comprising a clamp barfastening a strap in said one buckle part, said clamp bar forming endsreceived by said slots and projecting outwardly from the flanges throughthe slots, and being guided in the slots for translatory movement in itstransverse direction, said grooves formed by the legs of said cover,slidably receiving also said projecting ends of said clamp bar tomovably guide the cover on said flanges.

3. A buckle as claimed in claim 1, in which said leaf spring issubstantially W-shaped forming two median legs and two outer legs, andin which said stationary abutment is a pin, said median legs straddlingsaid pin and said outer legs bearing against said bar.

4. A buckle as claimed in claim 3, in which each of said outer legs isslit by longitudinal slots so as to form two tongues, one tongue bearingagainst the 'bar and the other tongue at engaged buckle bearing againstthe other buckle part thereby to urge the abutment means into bearingengagement with one another.

5. A buckle as claimed in claim 1, in which the buckle parts form flatsides and the bar forms an annular groove, and further comprising anelastic O-ring `which is disposed in said annular groove for resilientlykeeping the flat sides of the buckle parts in bearing engagement whenthe buckle parts are moved together into engagement at the abutmentmeans with the bar in latching position.

References Cited FOREIGN PATENTS 1,340,076 9/1963 France. 1,202,550 10/1965 Germany.

657,156 l0/1963 Italy.

BERNARD A. GELAK, Primary Examiner U.S. Cl. X.R.

